class_docstr: OpenAPIServiceToFunctions is responsible for converting an OpenAPI service specification into a format suitable
  for OpenAI function calling, based on the provided OpenAPI specification. Given an OpenAPI specification,
  OpenAPIServiceToFunctions processes it, and extracts function definitions that can be invoked via OpenAI's
  function calling mechanism. The format of the extracted functions is compatible with OpenAI's function calling
  JSON format.
  
  Minimal requirements for OpenAPI specification:
  - OpenAPI version 3.0.0 or higher
  - Each function must have a unique operationId
  - Each function must have a description
  - Each function must have a requestBody or parameters or both
  - Each function must have a schema for the requestBody and/or parameters
  
  
  See https://github.com/OAI/OpenAPI-Specification for more details on OpenAPI specification.
  See https://platform.openai.com/docs/guides/function-calling for more details on OpenAI function calling.
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docstr: Reads the content of a URL.
  :param url: The URL to read.
  :type url: str
  :return: The content of the URL or None if the URL cannot be read.
docstr_tok: ["Reads","the","content","of","a","URL",".",":","param","url",":","The","URL","to","read",".",":","type","url",":","str",":","return",":","The","content","of","the","URL","or","None","if","the","URL","can","not","be","read","."]
code: def _read_from_url(self, url: str) -> Optional[str]:
      """
      Reads the content of a URL.
      :param url: The URL to read.
      :type url: str
      :return: The content of the URL or None if the URL cannot be read.
      """
      try:
          response = requests.get(url, timeout=10)
          response.raise_for_status()
          return response.text
      except RequestException as e:
          logger.warning("Error fetching URL: %s. Error: %s", url, e)
          return None
  
file_path: haystack/haystack/components/converters/openapi_functions.py
imports: import json
  import logging
  import os
  from pathlib import Path
  from typing import List, Dict, Any, Union, Optional
  import requests
  import yaml
  from requests import RequestException
  from haystack import component, Document
  from haystack.dataclasses.byte_stream import ByteStream
  from haystack.lazy_imports import LazyImport
label_desc: Use image node_id 6 for calling the OpenAPIServiceToFunctions obj's underlying member method code with example usage: obj._read_from_url(url) and returns: response, None